Normal payments
Mortgage paid off in
YOUR MONEY. A CLEARER PICTURE.
Your mortgage.
A clearer way forward.
See what an extra £25, £50 or any monthly amount could do. Explore your full mortgage term, then compare overpaying with saving.
Explore your numbers ↓No sign-up. Figures stay in your browser.
YOUR FULL MORTGAGE TERM
What could your extra payment change?
OVER THE FULL REMAINING TERM
Total mortgage interest saved
With your overpayment
Mortgage paid off in
Your balance, all the way to zero
Full remaining term · mortgage balance only
Normal payments (dashed)With overpayments
Year-by-year balances and interest +
| Year | Normal balance | Overpayment balance | Normal interest | Overpayment interest |
|---|
Illustrative repayment mortgage model, not a lender quote or personal recommendation. Constant rate, monthly interest and month-end payments; no charges. Your normal payment stays unchanged and overpayments shorten the term. Check your lender’s allowance and early repayment charges. See the assumptions and reference links below.
THE OVERPAY OR SAVE CALCULATOR
Make the comparison yours.
02YOUR ILLUSTRATIVE COMPARISON5 years
Overpaying is ahead by
£183After comparing mortgage debt minus savings.
Overpay the mortgage
Mortgage debt minus savings
—- Mortgage remaining
- —
- Accessible savings built
- —
Save the extra money
Mortgage debt minus savings
—- Mortgage remaining
- —
- Accessible savings built
- —
See the difference develop
Mortgage debt minus savings · lower is betterOverpaySaveExact figures in the breakdown below
Year-by-year breakdownShow the numbers +
| Year | Overpay: debt | Overpay: cash | Save: debt | Save: cash | Overpay advantage |
|---|
An educational model, not a lender quote or a personal recommendation. Both paths use the same monthly budget. Existing savings and other assets are excluded and assumed equal.
CONFIDENCE COMES FROM CLARITY
No mystery behind
the numbers.
Start with the video example, then change one input at a time. The calculations use full precision; displayed values are rounded.
Explore UK Simplified on YouTube ↗What does this assume?
Repayment mortgage. Constant rates. Mortgage interest is the annual nominal rate divided by 12. Savings use the monthly equivalent of AER. Payments and deposits happen at month end. No fees, overpayment charges, missed payments or withdrawals. Savings are assumed accessible without restriction.
Normal mortgage payments stay unchanged. After either mortgage clears, that path saves its unused monthly budget at the same savings rate. A smaller final payment is allowed. Negative “debt minus savings” means savings exceed the remaining mortgage.
Why might my lender's figures differ?
Your lender may calculate interest daily, round payments differently or recalculate your payment. Remaining-term estimates and the payment date matter. Check your allowance, charges and whether your lender reduces the payment or brings repayment forward.
How are rates and tax compared?
A 5% mortgage rate divided monthly is approximately 5.12% effective annually in this model. AER already includes compounding. If savings interest is taxable, enter your estimated after-tax annual equivalent rate; this is a simplified scenario, not an allowance or tax-return calculation.
Formulas and reference links
Monthly mortgage rate r = annual rate ÷ 12. Normal payment = balance × r ÷ [1 − (1+r)−months]. At 0% it is balance ÷ months. Monthly savings rate = (1+AER)1/12 − 1.
- MoneyHelper: mortgage overpayment considerations ↗
- GOV.UK: tax on savings interest ↗
- Nationwide: an example of lender-specific terms ↗
References checked 12 November 2026. Model calculations are our own; these sources do not endorse individual results.
One money question.
A clearer next step.
We explain UK money matters through clear visuals and worked examples. This calculator accompanies our mortgage overpayments and savings explanations. It helps you explore the trade-offs—financial benefit, product rules and access to your cash.